Help a newbie with a basic hardware project

[tiffers]

Good Morning, (hey, it's morning _somewhere_ in the world right now!)

I sit here on a.org reading about all the neat (and astounding) projects going on and just wish I could do something myself. I've got the basics underhand after finished senior high school physics etc. (ALthough that _was_ 16 years ago *ouch*)

If I wanted to make my own kickstart rom switcher for an A500, what size parts do I need (ie physical dimensions of the ROM socket etc)

And what free software can I use to design the circuit and PCB and give files to someone to make the PCB(s) for me?

tiffers

[davideo]

Why not just ask if someone has got one going spare/cheap :idea:

It could be a lot more cost effective ;-)

In fact I have one spare - don't know what the p&p would be though but shouldn't be that expensive.

Dave G  8-)

[Illuwatar]

Free PCB software (for small projects): http://www.cadsoft.de/

I did just one like that for several years ago for my A500. As I remember, it was just a question of enabling one of the two ROM's. All pins was basically parallelled except for one of the chip-enable signals that was routed to a alternating switch. Making them low enables the chip, making it high turns the chip off (logically). I don't have the schematics available as this was before-internet time... (it was on some paper that has been lost)

[Astral]

Good Morning, (hey, it's morning _somewhere_ in the world right now!)

I don't know what time you posted this, but here in Gosford (Sydney), it's around 7:00pm - so Good Evening!  :-D

Good luck...

I was wanting to do the same thing myself, only for my A600. There are a few designs on aminet as far as I know, and most could probably be made using an easily available (from Dick Smith, Jaycar etc) vero (?) PCB board. I don't think you'll need to get a PCB custom made for this - it would be really unnecessary unless there was a complex design.

This is probably a good place to start as a lead up to more involved projects. You could just buy a board, but where is the fun and education in doing this? Go for it!

Oh yeah, and also...I finished senior physics about that amount of time ago also!

[skurk]

Well, from the top of my head, all you need to do is make a PCB which splits all pins from the original source to two destinations.  The A500 ROM is a 40-pin DIP IIRC, and simply add a switch on the CS line.

A PCB can be made online with services like expresspcb.com etc.

Ok, I said all that just to wave and say "hi!".  I'm in Sydney at the moment, just flew in from Brisbane after staying there for 5 days.

Heading downstairs to watch the game over an icy schooner.  Later mate, cheers.

[tiffers]

@davideo

As Astral posted above, where's the fun and education in that?  :-D

@skurk

Greetz! Enjoying our country?

Yes the kickstart ROM is a 40-pin DIP. Try buying a 40-pin DIP socket on digikey, and look at all the options you get *sigh*

Dick Smith seems to have what looks like the right type. Dual-wipe contact.. and surprisingly, they're only $0.78 each!  :-o Can anyone confirm these are the correct size?

The 'best' design on aminet for a 3 chip switcher has tracks on both sides, and describes the board as component side and solder side. Does this mean it has thru-the-board links for those tracks?

tiffers